In-premises networks run on in-premises cabling, such as phone line wires, power lines, cable TV lines and data network wiring, which are laid out for every separate unit, such as a house, an apartment or an office.
Power line communications (PLC) networks are either access networks, covering the link between a central office and the customer's premises, or home networks. Access networks may be used for supplying broadband access to homes, for automatic meter reading (AMR) and for other network diagnostics performed by electrical utility companies.
There are two basic types of home power line networks: low-speed and high-speed. The low-speed power line network is designed for command and control signals, setting up the so-called “smart home”, where electrical appliances and other devices may be controlled and monitored remotely. This low-speed network usually operates in the low-frequency band in the range 0-500 kHz.
The high-speed power line network is used for distributing broadband services inside the home. Applications may include web-browsing, IPTV, high-quality audio and video, etc. The frequency band used may vary according to the regulations in force in different countries.
A multitude of companies and organizations are developing PLC standards and technologies worldwide. One of the dominant is the HomePlug consortium which released its high speed home networking specification HomePlug AV in December 2005. Another consortium is the Universal Power line Alliance (UPA), which promotes a technology developed by Digital Systems on Silicon (DS2). Panasonic has developed a proprietary PLC technology, called High-Definition PLC (HD-PLC) and two standards committees, the IEEE P1901 and the ITU-T Q4/15 (under the G.HN project), are both working to set standards for power line communications.
The existing networks are designed to communicate at high speeds (around 200 Mbps). However, due to the nature of home power lines, they rarely succeed.